Calendar calculating in savants with autism and healthy calendar calculators.
BACKGROUND
Calendar calculation is the ability to quickly name the day that a given date falls on. Previous research has suggested that savant calendar calculation is based on rote memory and the use of rule-based arithmetic skills. The objective of this study was to identify the cognitive processes that distinguish calendar calculation in savant individuals from healthy calendar calculators.


METHODS
Savant calendar calculators with autism (ACC, n=3), healthy calendar calculators (HCC, n=3), non-savant subjects with autism (n=6) and healthy calendar calculator laymen (n=18) were included in the study. All participants calculated dates of the present (current month). In addition, ACC and HCC also calculated dates of the past and future 50 years.


RESULTS
ACC showed shorter reaction times and fewer errors than HCC and non-savant subjects with autism, and significantly fewer errors than healthy calendar calculator laymen when calculating dates of the present. Moreover, ACC performed faster and more accurate than HCC regarding past dates. However, no differences between ACC and HCC were detected for future date calculation.


CONCLUSIONS
The findings may imply distinct calendar calculation strategies in ACC and HCC, with HCC relying on calendar regularities for all types of dates and an involvement of (rote) memory in ACC when processing dates of the past and the present.
Dubischar-Krivec
A M
AM
Institute of Medical Psychology and Behavioral Neurobiology, Eberhard Karls University, Gartenstrasse 29, Tübingen, Germany. anna.dubischar@uni-tuebingen.de
Neumann
N
N
Poustka
F
F
Braun
C
C
Birbaumer
N
N
Bölte
S
S
D000293:Adolescent; D000328:Adult; D001076:Aptitude; D001321:Autistic Disorder / Q000175:diagnosis / Q000523:psychology*; D002648:Child; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008433:Mathematics; D011939:Mental Recall; D011340:Problem Solving; D011930:Reaction Time; D012016:Reference Values; D055815:Young Adult